Is this Britain’s most influential book reviewer?

Screen time stops children reading, according to parents and teachers. Which eight-year-old has time to dip into Enid Blyton, when they are busy playing Pokémon Go and their attention span has been reduced to that of a gnat by endless YouTube videos?

But the dire warnings don’t quite stack up. At least, not in a corner of Hertfordshire, where Ruben Joseph, aged 11, has used his fondness for technology to set up a website for children’s literature. Called Mango Bubbles, it is a review site, where hundreds of children’s books have been reviewed – all by children.

In the two years since it was launched it has started to make waves in the children’s publishing industry and catch the eye of children’s authors.

But Ruben is remarkably blasé about the venture, which started because he was bored – and a bit jealous of his older cousin, who had set up his own website as part of a history project.

“Mum was sitting on the sofa, and I was sitting on the rug in the living room and I said 'Mum, I want a website’. I thought it would be really cool to have my own site.”

At this point, he was keen – as many nine-year-olds are – on setting up a gaming website. But then he fell out of love with Minecraft, the enormously popular brick-building game, and his mother pointed out that creating games was quite a complex task.

“Then I said, how about book reviews,” says Ruben. And thus Mango Bubbles was born.

This is quite rare. It’s by children for children. There’s no ulterior motivePiers Torday

I am talking to Ruben in an independent bookshop in north London, along with his mother Louise Morriss (divorced from Ruben’s father), who runs a PR company that helps charities with their marketing. She insists that the idea and impetus was entirely Ruben’s. “I said the secret of a good website is that you have to keep on adding content. So, I said if you can promise to write a few book reviews over a period of time, I’ll help you set up a Wordpress site.”

This is the platform that many bloggers use to publish their work online – it is free and relatively easy to use if you are regular computer user.

The first book reviewed was You’re a Bad Man Mr Gum by Andy Stanton, one of Ruben’s favourite authors, along with Agatha Christie. He says he likes any “sad books, where people have fatal diseases and at the end of the book they die”.

The name of the site, Mango Bubbles, is a tribute to Stanton, who has a character called Friday O’Leary, but who goes by the nickname Mungo Bubbles. “And because I enjoy eating mangoes, I decided to change it to Mango Bubbles,” says Ruben.

Initially, the site published just a couple of reviews, written by Ruben. But when he gave a presentation at school, some of his friends asked to submit their reviews too.

So far, 50 reviewers have contributed – all under the age of 18, and all of them almost entirely unedited. Most of the reviewers are people Ruben has never met but who have stumbled across the website. Some reviews are just a few sentences long and involve lots of exclamation marks – “I like exclamation marks”, says Ruben – other are fully-formed critiques.

Ruben with mum LouiseCredit:
Heathcliff O’Malley for The Telegraph

Before long the site caught the eye of various children’s authors. Louise says: “I was at work, and taking a sneaky look at the website, and on Wordpress you can see where people have come from, and there seemed to be lots of people coming via an author’s website.” The author was Helen Moss, who has written a series called Adventure Island – a modern version of the Secret Seven – and she talked about Mango Bubbles on her website.

“I was so excited,” Louise says. “The kids were on a school trip, but I had the teacher’s mobile number and phoned her. They were on a train carriage, and the teacher yelled out the news and they were all screaming.”

Since then, the site has slowly grown. It is still relatively small – only two to three reviews get posted every week, and it receives a few thousand clicks a month rather than a few million. But it is starting to make waves.

Steve Cole, the children’s author who wrote the Astrosaurs series, says: “When I write I am not thinking of what might appeal to a prize panel or adult reviewer. I am fully focused on hurtling a child reader from chapter one to the last sentence (in any order they prefer).

“­If an adult doesn’t fully approve, that can be a good thing – a children’s book should be for the child. And a book blog that communicates a child’s enthusiasm for a child’s book is a brilliant thing.”

Cole is so impressed by the project – “I think it’s wonderful and so worthwhile” – that he dedicated a recent book, Invisible Ink, to Ruben.

I think people can see it’s Ruben driving it, and it wouldn’t happen if he didn’t want to do itLouise Morriss

The children’s newspaper First News runs reviews of children’s books, written by children; so too some other websites. But Mango Bubbles is the only time, according to people in the industry, that one has been set up by a child. “This is quite rare – it’s by children for children,” says Piers Torday, one of the most popular children’s authors of the moment. “There’s no ulterior motive. They review what they want to review.”

Statistics suggest children’s literature in Britain is enjoying a golden period. The children’s book market is on course for an 11.7 per cent increase to £394 million this year – making 2016 the biggest year for children’s books for the third year in a row, according to Nielsen Bookscan, the research firm that tracks the market.

But some of this boom is fuelled by just a handful of celebrity authors: David Walliams, David Baddiel and, of course, JK Rowling. Despite the final Harry Potter novel being published nine years ago, the franchise rolls on.

“The children’s market is in massive growth at the moment, which is fantastic,” says Torday. “But it also means it is very competitive. Publishers are overstretched when it comes to promotion. So you have to find a way to reach readers.”

Children’s authors are discovering that they have to work harder than ever to promote their books. For most, that involves visiting schools and children’s literary festivals regularly, but a review on Mango Bubbles can make a difference.

The website’s success means that Ruben is not only being sent books prior to publication by publishers, but he’s also been asked to interview authors on stage at his local Hertford Children’s Book Festival; he even organises Mango Day – where authors come to speak at his (now, former) primary school.

“I’ve met Julia Donaldson. She was really nice. And Steve Cole, I’ve met him quite a few times. It just feels like he’s my friend,” says Ruben.

Ruben insists that his recognition on the children’s book circuit has not gone to his head. “My friends don’t treat me differently from anyone else. I’m just a normal person.”

I ask Louise whether she worries she might be seen as a pushy mother. “No,” she says and does a nervous laugh. “Should I?” This is clearly first time she’s thought about this. “I think people can see it’s Ruben driving it, and it wouldn’t happen if he didn’t want to do it.”

For now, the site makes no money whatsoever, and it has a charming unglossy feel. Ruben knows that as he grows up, and starts to review more grown-up books, the site needs to keep recruiting children to review books aimed at primary school pupils. “Adults can’t review books on the site,” he says firmly, explaining how the few reviews of children’s books written by adults that he has read had missed the point and were “too wordy”.

His ultimate ambition is to become an author himself, and he says he’s tried to write a book. I ask what genre. “Realistic fiction, where lots of people die.”

It sounds fun. And looking at what he’s achieved so far, I wouldn’t bet against it being published.